The present invention relates to a plasma processing apparatus for processing a wafer placed in a processing chamber in a vacuum vessel by use of plasma generated in the processing chamber, and in particular, to a plasma processing apparatus in which the wafer is processed while adjusting temperature of a sample stage disposed in the processing chamber to thereby adjust temperature of the wafer suitable for the processing.
Such plasma processing apparatus processes a so-called multilayered film including a plurality of films which are objects of the processing and which are formed in a surface of a sample having a contour of a substrate, for example, a semiconductor wafer. To minimize the period of time required to process the multilayered film, it has been considered to process films vertically adjacent to each other of the wafer in the same processing chamber without moving the wafer to the outside of the processing chamber between the processing phases respectively of the adjacent films. It has been required to conduct finer manufacturing of a wafer with high precision. To obtain higher uniformity in the contour of the wafer in the surface direction (radial and circumferential directions) thereof after the manufacturing processes of the wafer, for example, after the films of the wafer are etched, the wafer temperature is adjusted for each film to be suitable for the associated processes in the prior art.
A technique to adjust the wafer temperature has been described in, for example, JP-A-2008-300491. According to the technique, a disk-shaped ceramic member and a heater disposed therebelow to be connected to the ceramic member are arranged in an upper section of a sample stage, the upper section providing a surface on which a wafer is to be placed. By adjusting quantity of heat generated by the heater, the temperature of the ceramic disk member and that of the wafer disposed on an upper surface of the disk-shaped ceramic member are set to temperature values suitable for the associated processes. In JP-A-2008-300491, the disk-shaped ceramic member includes therein an electrode to receive direct-current (dc) power to generate electrostatic force to chuck the wafer onto the upper surface thereof. On a lower surface of the disk-shaped ceramic member, a film-type heater having a predetermined thickness is formed. Peripheral sections of the heater are coated with resin adhesive. A side section of the disk-shaped ceramic member coated with the adhesive is pushed against an upper surface of the main section made of conductive material of the sample stage with the adhesive therebetween, to thereby form the sample stage.
The heater includes a material prepared by mixing conductive material and semiconductor material with a heatproof resin and is supplied with power via a connector disposed in a through hole arranged in the main section of the sample stage. The sample stage is constructed such that two areas, i.e, an area near a central section of the sample stage and an area in a circumferential section thereof are supplied via respective connectors with respectively different values of power. Hence, in each of the sample stage and the wafer arranged thereon, the temperature distribution varies between the central section and the circumferential section thereof.